Front Pull-Out Hydraulics For Pumps

ABSTRACT

In one embodiment of the disclosure, a dish insert may be installed in a pump head such that the dish insert may be removed from the reagent head side of the pump head. Port holes permit movement of hydraulic fluid through the dish insert. The dish insert may be affixed to the pump head by fasteners. The dish insert may include removal means. For example, removal holes may be provided wherein fasteners may be threaded until the fasteners “bottom out” on the pump head. In this way, fasteners may force the dish insert out of the mounted position by acting against the threads as a jack screw.

FIELD OF THE INVENTION

The present invention relates to pumps, and more specifically, to hydraulic systems used with pumps.

BACKGROUND OF THE INVENTION

Metering pumps are typically used to pump liquids in precise amounts and/or flow rates, but may be used simply to transfer liquids from one area to another. Some pumps operate by using a piston to draw fluids being pumped (“process fluids”) into, and push the process fluids out of, a pumping chamber.

Other pumps operate by using a piston which may operate in hydraulic fluids. In these pumps, a diaphragm may separate the hydraulic fluid from the process fluid. Forward movement of the piston transmits hydraulic force against the diaphragm. The diaphragm moves in relation to the piston and forces process fluid through an outlet check valve. Conversely, rearward movement of the piston causes the diaphragm to suction process fluid from an input check valve into a reagent head.

In this way, the forward and rearward movement of the diaphragm causes a cycle of pressurization (forcing process fluid out of the head) and suction (drawing process fluid into the head). Other similar pump styles are known in the art, for example plunger pumps.

The pistons of such pumps incorporate a primary seal. Maintenance of the primary seal typically requires either removal of the piston assembly or removal of the cylinder in which it reciprocates. This work generally requires significant disassembly and removal of the pump from its operating position to a maintenance facility and/or removal of most if not all of the hydraulic portion.

Similarly, maintenance of a hydraulic accessory, such as a Hydraulic Performance Valve (“HPV”), may require significant disassembly and removal of the pump from its operating position and major disassembly of the hydraulic portion. Required maintenance of the drivetrain may similarly require the removal of the entire pump from the operating position.

Accordingly, there is a need for a pump which may be serviced with less disruption to the surrounding operating system in which the pump is installed.

SUMMARY OF THE INVENTION

The present disclosure meets the above described need by providing a pump with a front pull-out dish, piston, and/or hydraulic assembly. Similarly, the drivetrain of a pump according to the disclosure may be removed without disconnecting the wet end. In this way, maintenance of certain parts and seals including, but not limited to, the primary seal, and various hydraulic valves, may be accomplished without significant disassembly and removal of the drivetrain. Similarly, replacement of drivetrain components can be accomplished without disconnecting the wet end of the pump. The pump may not need to be removed from the pumping location. Maintenance time and cost may be significantly reduced.

It should be noted that while reference is made throughout the instant disclosure to metering pumps, the technology described herein applies equally to any type of reciprocating pump, and such matter is intended to fall within the scope of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated in the drawings in which like reference characters designate the same or similar parts throughout the figures of which:

FIG. 1 a is a side view of a pump according to an embodiment of the invention;

FIG. 1 b is an end view of the pump of FIG. 1 a;

FIG. 1 c is a cross section view of the pump of FIGS. 1 a and 1 b;

FIG. 2 is a view of a diaphragm support according to another embodiment of the invention;

FIG. 3 a is a front view of the dish insert of FIG. 2;

FIG. 3 b is a cross section view of the dish insert of FIG. 3 a, taken along A-A;

FIG. 3 c is a cross section view of the dish insert of FIG. 3 a, take along B-B;

FIG. 3 d is a side view of the dish insert of FIG. 3 a;

FIG. 3 e is a top view of the dish insert of FIG. 3 a;

FIG. 3 f is a perspective view of the dish insert of FIG. 3 a;

FIG. 4 a is a front view of a dish insert according to another embodiment of the present invention;

FIG. 4 b is a cross-section view of the dish insert of FIG. 4 a;

FIG. 5 a is a front view of a dish insert according to another embodiment of the invention;

FIG. 5 b is a cross-section view of the dish insert of FIG. 5 a;

FIG. 6 a is a front view of a dish insert according to another embodiment of the invention;

FIG. 6 b is a cross-section view of the dish insert of FIG. 6 a;

FIG. 7 a is a front view of a dish insert according to another embodiment of the invention;

FIG. 7 b is a cross-section view of the dish insert of FIG. 7 a;

FIG. 8 a is a view of an alignment pin;

FIG. 8 b is a cross section view of a keyway;

FIG. 9 a is a front view of a piston according to another embodiment of the invention;

FIG. 9 b is a cross-section view of the piston of FIG. 9 a;

FIG. 10 a is a front view of a piston according to another embodiment of the invention;

FIG. 10 b is a cross-section view of the piston of FIG. 10 a;

FIG. 11 a is a front view of a piston according to another embodiment of the invention;

FIG. 11 b is a cross-section view of the piston of FIG. 11 a;

FIG. 12 a is a front view of a piston according to another embodiment of the invention;

FIG. 12 b is a cross-section view of the piston of FIG. 12 a;

FIG. 13 a is a front view of a piston according to another embodiment of the invention;

FIG. 13 b is a cross-section view of the piston of FIG. 13 a, taken along A-A;

FIG. 13 c is another cross-section view of the piston of FIG. 13 a;

FIG. 14 a is a front view of a piston according to another embodiment of the invention; and

FIG. 14 b is a cross-section view of the piston of FIG. 14 a.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 a-1 c depict a pump head 10 according to one embodiment of the disclosure. The pump head 10 may comprise a connecting rod 12 in a cylinder 13, driven by a drive train (not shown) which may include a drive motor. The connecting rod 12 may be reciprocally driven by the drive train and may, in turn, drive a piston 14. The piston 14 may operate in hydraulic fluid. A diaphragm 16 may separate the hydraulic fluid from the process fluid. The piston 14 may be moved rearward (toward the drive train), thereby drawing the diaphragm 16 back toward the piston 14. In this way, a pumping chamber 18 may expand in volume. The diaphragm 16 will move back until drawn up against a diaphragm support 19 which includes a dish insert 20.

The piston 14 may cycle forward (toward the pumping chamber 18). This may cause the diaphragm 16 to move forward, thereby reducing the size of the pumping chamber 18. The expanding and contracting pumping chamber 18, along with check valves 22, 24, serves to move process fluid through a reagent head 26.

In one embodiment of the disclosure, the dish insert 20 may be installed in the pump head 10 such that the dish insert 20 may be removed from the reagent head 26 side of the pump head 10. FIG. 2 depicts an partial end view of a pump head 12 with the reagent head 26 removed showing the diaphragm support 19 including the dish insert 20. Port holes 28 permit movement of hydraulic fluid through the dish insert 20. The dish insert 20 may be affixed to the pump head 12 by fasteners 30. Fasteners 30 may pass through mounting holes 32 in the dish insert 20 and thread into holes in the pump head 12 (not shown). Fasteners 30 may be countersunk such that fasteners 30 do not protrude above the surface of the dish insert 20 when secured. In this way, the diaphragm 16 is protected from unnecessary contact with fasteners 30. The arrangement of fasteners 30 may be such that the dish insert 20 has only one possible orientation in the pump head 12, while still providing sufficient securing force. For example, the fasteners may be offset or asymmetrical. In FIG. 2, an embodiment in shown wherein the fasteners 30 are arranged near the perimeter of the dish insert 20 (to provide sufficient mounting force), but not evenly distributed about the circumference (to allow only one orientation of the dish insert 20 in the pump head 12).

Dish inserts according to the instant disclosure may include removal means. FIGS. 3 a-3 f depict a dish insert 40 according to another embodiment of the instant disclosure. Dish insert 40 may be affixed using mounting holes 42. Removal holes 44 are provided for easier removal of the dish insert 40 from a pump head. Removal holes 44 may be threaded, through holes. When removing the dish insert 40 from a pump head, fasteners are removed from mounting holes 42 and the same fasteners or different fasteners may be threaded into the removal holes 44. Fasteners may be screwed into the removal holes 44 until the fasteners “bottom out” on the pump head 10. In this way, fasteners may force the dish insert 40 out of the mounted position by acting against the threads as a jack screw. Peripheral edges 43, 45 of the dish insert 40 may be chamfered for easier insertion and removal. Chamfered edges also allow for less wear on a diaphragm where the dish insert 40 meets the pump head.

FIGS. 4 a and 4 b depict another embodiment of a dish insert 46 according to the instant disclosure wherein removal holes 48 are threaded blind holes. When fasteners are threaded into the removal holes 48 of a dish insert 46 of this embodiment, fasteners will protrude above the front surface of the dish insert 46. In this way, fasteners may be used to pull the dish insert 46 from its mounted position (with or without tools).

FIGS. 5 a and 5 b depict another embodiment of a dish insert 50 according to the instant disclosure wherein a cantilever lip 52 is disposed along the periphery of the dish insert 50. The cantilever lip 52 may be engaged with a removal tool to pull the dish insert 50 from its mounted position. The cantilever lip 52 may protrude from the dish insert 50 (as shown) or may be recessed into the dish insert (not shown) and scale may vary from that shown.

FIGS. 6 a and 6 b depict another embodiment of a dish insert 54 according to the instant disclosure wherein clearance notches 56 are incorporated at one or more positions the periphery of this dish insert 54. Clearance notches 56 may be engaged by hand or with a tool to pry or pull to dish insert 54 from its mounted position.

FIGS. 7 a and 7 b depict another embodiment of a dish insert 58 according to the instant disclosure wherein a retaining tube 60 may be utilized to align and retain the dish insert 58 in the mounted position. Any of the removal hole configurations may be used to remove the dish insert 58 from its mounted position.

FIG. 8 a depicts where orientation of the dish insert 62 may be facilitated by an alignment pin 64. The alignment pin 64 may be affixed to the dish insert 62 and mate with a alignment hole in the pump head 68. Alternatively, the alignment pin 64 may be affixed to the pump head 68 and mate with an alignment hole in the dish inserts 62. The alignment pin may be configured as a key and thus fit within a key way of the mating surface so as to retain as well as align/orient the dish insert 62 in the mounted position (see, e.g., FIG. 8 b). Those having skill in the art will recognize alternative alignment means, including but not limited to, ridges.

Removal of a dish insert allows for servicing of various components, as well as access to the piston/primary seal of the pump head.

Piston removal has long required significant disassembly of the pump head and may typically require removal of the pump head and possibly removal of other larger sections of the pump. However, a pump according to the instant disclosure may use alternative means for piston and piston assembly design which may allow removal of the piston from the reagent head side of a pump. FIGS. 9 a and 9 b depict an embodiment of a piston 80 according to the instant disclosure wherein one or more (in this case two) removal holes 82 may be used to remove the piston 80 from a cylinder (not shown). In this embodiment, the removal holes 82 are threaded, blind holes in which a fastener may be threaded. As such, the protruding fastener will allow removal of the piston 80 by hand or with a tool.

In order to remove a piston 80 in this way, the piston must be disconnected from a connecting rod 12. The piston may be affixed to a threaded connecting rod 12 with a nut. Alternatively, a cotter or similar pin or snap ring may be used; alternatively, the piston may be threaded. Those having skill in the art will recognize other methods of affixing the piston to the connecting rod.

FIGS. 10 a and 10 b depict another embodiment of a piston 84 according to the instant disclosure having four removal holes 86. FIGS. 11 a and 11 b depict an embodiment of a piston 88 according to the instant disclosure having two removal holes 90 positioned toward the radial inside of the piston 88 and two removal holes 92 positioned radially toward the outside of the piston 88.

FIGS. 12 a and 12 b depict another embodiment of a piston 94 according to the instant disclosure having a clamping ring 96. A tool may be adapted to engage the clamping ring 96 for removal of the piston 94. Similarly, FIGS. 13 a-13 c depict a piston 95 having one or more cantilevered lips 97 to which a tool may engage for removal of the piston 95.

FIGS. 14 a and 14 b depict another embodiment of a piston 98 according to the instant disclosure wherein the piston includes one or more keyways or slots 99 to which the keys 100 of a removal tool may engage for removal of the piston 98.

According to an embodiment of the instant disclosure, the drive end of a pump may be removed from the pump head 10 such that the drive train (dry/drive end) of the pump may be removed and serviced, repaired, or even replaced, without disturbing the pump head and reagent head (wet end). Drivetrain bolts 15, or other connection means, may facilitate the connection of the drivetrain to the pump head 10 in such a case. Alignment features, such as, for example, mating pilots, may be used to facilitate quick and proper positioning between the drivetrain and the pump head.

While the invention has been described in connection with certain embodiments, it is not intended to limit the scope of the invention to the particular forms set forth, but, on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention. 

1. A metering pump, comprising: a pump head having a drivetrain side and a reagent side; a dish insert, arranged in the of the pump head; at least one fastener to removably attach the dish insert to the pump head; and removal means for removing the dish insert from the pump head by way of the reagent side. 